Combination of a single-station reverse osmosis device with a hemodialysis device

ABSTRACT

A combination of a single-station reverse-osmosis (RO) device comprising a hemodialysis device (HD device) is characterized in that at least one cleaning chamber for the raw water and/or for the permeate is arranged, and that upon request by the HD device the permeate flows either via the water inlet valve into the HD device or via a flushing valve of the HD device to an outlet.

FIELD OF THE INVENTION

It is the objective of this development to feed consumers, particularlyhemodialysis devices, with high-purity permeate of a chemically andhygienically high quality at low costs while keeping the installationefforts as small as possible.

Further applications of this development for other fields, e.g. forlaboratory or biology or also pharmacy technology, as a device for thepreparation of high-purity flushing liquid, or also for the productionof liquid for making medicaments, cell cultures or the like areconceivable and feasible.

BACKGROUND OF THE INVENTION

Especially in the hemodialysis field, central-supply reverse-osmosissystems are normally used with permeate supply lines that have to beinstalled in a correspondingly complicated way. Serious drawbacks of thecentral reverse-osmosis systems are on the one hand the high risk ofnon-treatment in the case of device failure and on the other hand thehigh installations costs and the difficult hygienic safety of theinstallation.

Single-station reverse-osmosis systems are mainly used for reasons ofspace in the intensive-care fields. For the chronic hemodialysis (HD),the supply of the dialysis devices with permeate by single-stationreverse osmosis (RO) systems is not feasible at the moment for reasonsof costs.

Further problems arising in the combination of RO system and HD deviceare posed by the missing evidence that the permeate supply device has nodead spaces for reasons of bacterial input into the HD device and can bedisinfected completely.

To this end an integrated chemical or thermal disinfection of thedistribution system, including the HD devices, is carried out accordingto the prior art.

Another serious flaw is the decreasing efficiency and service life ofthe reverse osmosis membrane due to irreversible deposits, the reasonbeing that biomass and hardly soluble salts are often contained in thesupply water for the RO system.

SUMMARY OF THE INVENTION

It is therefore the purpose and aim of the invention to ensure thepermeate supply of a HD device with minimal technical efforts togetherwith a constantly high membrane performance and the best microbiologicalquality.

This object is efficiently achieved in that the RO system preferablycomprises a disposable, i.e. single-use, membrane and is equipped bytaking only minimal technical efforts in such a manner that the fullfunction will only be noticed upon coupling with the HD device in such amanner that on the one hand the permeate supply takes place in achemically irreproachable way and without any dead space owing to thejoint use of functional elements and that on the other hand it ispossible due to the communication between HD device and RO system to usewater and energy in a way that helps to save resources.

With great advantage, valves of the HD device are here used for therelease or the flushing of the high-purity connection line.

The preventive disinfection of the high-purity connection line to the HDdevice takes a prominent position. To this end the inventionadvantageously provides a cleaning chamber in the permeate collectiontube of the reverse osmosis membrane.

Advantageously, a cleaning chamber is also provided at the primary sideof the reverse osmosis system.

The function of the cleaning chambers is on the one hand thedecontamination of the microorganisms and on the other hand thestabilization of the hardeners, so that efficiency-reducing deposits onthe reverse-osmosis membrane are prevented.

This is accomplished through the construction of the cleaning chamberwhich allows an electrical or magnetic or electromagnetic orelectrolytic or sonographic effect or a combination of differentphysical effects of the liquid flowing therethrough. It has beendetected in experiments that electrolysis takes place by means of awater irradiation frequency in the VHF range of preferably 13.56 MHz.This form of the cleaning chamber can also be used as a decontaminationdevice.

Microorganisms are here either oxidized or they are prevented byelectrical pulses from multiplying or their multiplication is diminishedby said pulses.

The physical anti-lime function consists in the stabilization of thelime dissolved in the water in such a manner that the normally largewater molecule clusters with their dipole-like electrical charge arebroken up and arrange themselves such that predominantly very tiny watermolecules clusters are formed that do not tend to precipitate or onlyshow a minor tendency to precipitation.

The use and the place of installation of the cleaning chambers arehowever not limited to the described function.

Since the disinfection action of the electrolytically produced oxygenradicals as well as the stabilization of the lime crystals in the liquidare only temporary after the cleaning chamber has been switched off, theflow-resistance means of the RO system is advantageously openedperiodically and/or at the end of an operating cycle by means of abypass valve. This suddenly increases the flow in the primarycirculation circuit and the surfaces of the liquid-conducting componentsare flooded and flushed.

To support the disinfecting action, the membrane collection tube or themembrane and spacer materials may be coated with anti-microbiocidalagents.

Since the action of the cleaning chamber cannot directly be detected bythe user by way of its physical effect or its effects on crystalformation or contamination, a cleaning sensor may advantageously beprovided for primary and secondary circuit.

Components or liquid-conducting lines may here be designed withtransparent or translucent material to check the contamination visuallyor electro-electronically.

In an advantageous configuration the transmitter/receiver unit isarranged in one plane. The optical transmitter signal is here projectedonto an opposite reflecting surface and is reflected from there to theoptical receiver.

A further configuration of the contamination sensor is that the sensordetermines the deposition of biological dirt layers in that thisdeposition reflects, by irradiation e.g. with UV light, a fluorescent,measurable response signal corresponding to the layer thickness.

With great advantage, in order to improve the impact in time and toenhance the physical cleaning effects, an additional circulation pumpcan be connected with a cleaning chamber between the concentrate outletand the mixed water inlet. This may be an additional cleaning chamberwith a different physical effect with respect to the cleaning chamber.

A flow through the primary circuit in the sense of an optimaloverflowing of the membrane is here ensured, namely substantiallyindependently of the action of the pump used for mixed-water supply,pressure build-up and circulation performance.

Owing to this invention both a controlled preventive avoidance of thebiofilm in the primary circuit of the membrane and a cost-savingdisinfection of the permeate supply without dead spaces are possible.

It is conceivable that the reverse-osmosis membrane indicated in thisinvention will soon be replaced—due to the rapid development ofselective hollow-fiber membranes—by a combination which is similar tothis invention and made up of HD device and upstream hollow fiber typesoftener/sterile filter membrane which can be produced at lower costs.The present invention will also cover this field on condition that thesame process-technological tasks are concerned.

As is generally known, the functional principle of reverse osmosissystems consists in that the water to be treated is guided in a filtermodule under pressure along the surface of a semipermeable membrane,with part of the water, the so-called permeate, passing through themembrane and being collected at the other side of the membrane andsupplied to the points of consumption. The part of the raw water thatdoes not pass through the membrane and is enriched with retainedsubstances, the so-called concentrate, flows at the end of the flowsection of the primary circuit out of the membrane module.

In the case of selective hollow-fiber membranes, a filtration method ishere also concerned in which specific substances in the water areretained to filter a liquid which can be used for the hemodialysistreatment. In this case the application of oxidizing disinfectants andthe use of cleaning cells at the secondary side have to be slightlyadapted with respect to material compatibility and design.

The following text describes the use of the RO membrane.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a combination of a reverse osmosis system with ahemodialysis device.

FIG. 2 shows a second embodiment of a combination reverse osmosis systemwith a hemodialysis device with an added buffer chamber.

FIG. 3 shows a cleaning cell for the permeate collection tube.

FIG. 4 shows a cleaning cell for the water supply line.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The scheme in FIG. 1 represents the combination of a reverse osmosis(RO) system (1) with a hemodialysis device (HD device) (21) and thecooperation of joint functional elements.

The raw water to be treated flows out of the feeding line (49) via thevalve (18) through a cleaning chamber (17) into the pressure tube (3)which is equipped with an RO membrane (4). The primary circuit of the ROmembrane and of the water supply channels (10) is separated by thesemipermeable membrane (11) from the secondary circuit (9) and thepermeate pockets, respectively.

The permeate flows out of the permeate pockets (9) through the permeatecollection tube perforations (13) via the permeate collection tube (5)and connection line (19) to the HD water or permeate inlet valve (23) ofthe HD device (21).

Flawed permeate produced in excess or measured by the conductivity cell(20) can flow at the end of the line (19) via an inserted HD flushingvalve (22) with pressure-maintaining function to the outlet (33).

The pressure needed for filtration in the primary circuit of the ROfilter (2) is produced with a flow-resistance means (35) which isinserted into the concentrate line (36) downstream of the RO filter,e.g. in the form of a throttle valve or a pressure-maintaining valve.

When permeate is requested by the HD device (21), the water inlet valve(18) opens, and after release by the LF cell (20) the HD device is fedvia the HD water inlet valve (23).

In the case of an inadequate permeate quality or also in the case ofnecessary flushing programs, the HD water inlet valve (23) is closed andthe flushing valve (22) of the HD device is opened, so that the unusedpermeate or the flushing liquid flows via the flushing line (26) to theoutlet (33).

In the HD device 21 the introduced permeate is prepared via thedegassing throttle (27), the pump (25) of the HD device, the heater (29)and the degassing chamber (30) for the HD treatment. The HD deviceincludes a circulation line (31) and a concentrate and bicarbonatesupply means (32).

The permeate collection tube (5) comprises an accommodating means (8)for a cleaning cell (16) the electrodes (40) of which output oxidantsinto the permeate, e.g. oxidants such as atomic and or elementary oxygenor ozone or OH hydroxyls or radio waves for producing oxidants.

The oxidant produced is passed together with the permeate through theline (19) and the flushing valve (22), which is first opened, to theoutlet (33).

In order to reduce the flushing flow, the valve (22) can here beclocked. It is also possible to include an additional flow-resistancemeans (not shown).

Now shown is an impurity cell for detecting organic or inorganicdeposits, both within the concentrate line (36) and in the permeate line(19).

To avoid deposits at the primary side of the membrane, i.e. on theinside of the pressure tube (3), the liquid channels (10) and theoutflow line (36), the cleaning cell (17) can also be activated duringthe flushing and also the feeding process for the HD device 21.

Preferably, the flushing valve (34) is opened at cyclic flushingintervals and the whole primary circuit 10 has liquid flowingtherethrough and is flushed.

The illustrated actuators and sensors can be controlled by the HD deviceand also by HD device and RO system in combination. The spatialarrangement of these functional elements as a part of the HD device isalso possible.

FIG. 2 additionally shows a buffer chamber (37) which serves on the onehand the faster permeate supply into the HD device (21) and on the otherhand the generation of a negative transmembrane pressure. When anegative transmembrane pressure is produced, the filtering direction isreversed by interrupting the water supply (49) and by opening theflushing valve (34). In this process, the permeate which is contained inthe buffer vessel (37) flows back via the permeate pockets (9) to theprimary side (10), thereby loosening the deposits positioned on themembrane surface (11). With the opening of the water supply means (49)these are washed away to the outlet (33).

Pump (39) raises the pressure in the primary circuit and therebyimproves the filtering capacity.

The circulation pump (38) also enhances the performance, and especiallycontributes to the saving of water, in that the overflow at the primaryside gets a greater proportion in relation to the permeate performance.

FIG. 3 schematically illustrates a cleaning cell with 2 electrodes (40)that can be introduced sealingly in form-fit fashion into the permeatecollection tube as anode, cathode and cation exchanger membrane aselectrolysis cell.

FIG. 4 shows by way of example the configuration of a cleaning cell (17)with 3 electrodes, the middle electrode (44) being isolated in space andelectrically from the two outer electrodes (43).

It is possible by way of a material selection and by way of theelectrical connection type to operate the cleaning chamber (17) as anelectrolysis cell or as an electromagnetic cell or as a cell withelectrode connections for current and voltage, also capacitively.

A pole of the electrical supply device is here preferably applied to thebridged outer electrodes (43), and the other pole is applied to themiddle electrode (44).

During operation of the cleaning chamber (17) as the electrolysis cellthe two outer electrodes (43) are the cathodes and the middle electrode(44) is the anode. When used as an electrolysis cell, it is advantageousfor the achievement of a higher efficiency to separate anodes andcathode chamber by cation exchanger membranes. Due to the lowpermeability of this membrane the arrangement of anode, membrane,cathode has to be modified to achieve a configuration (not shown) whichis advantageous from the viewpoint of fluid technology.

This electrolysis cell serves to produce oxygen radicals for theinactivation of the microorganisms or also serves to reduce limescale.

FIG. 4 shows the structure of a combined cleaning chamber (17) with 3electrodes and a coil winding (45).

Decalcification is here carried out via the force lines of thecoil-generated magnetic field in the liquid.

The use of Teflon-encapsulated ring magnets in the liquid or ringmagnets outside the isolating piece (48) instead of the coil winding(45) is possible.

In addition to the illustrated representations, various pre-filtrationand post-filtration components are possible, such as e.g. additionalinput filters, as carbon, ultra-filter, or also as safety filter—sterilefilter as post-filter.

1. Reverse osmosis (RO) 2. RO filter 3. Pressure tube 4. RO membrane 5.Permeate collection tube 6. Connection: water supply/pressure tube 7.Connection: concentrate 8. Permeate collection tube: accommodation meanscleaning cell 9. Secondary side/permeate pockets 10. Primarycircuit/side/water supply channels 11. Membrane 12. Outer membranejacket 13. Permeate collection tube - perforations 14. Permeate pocketgluing 15. Pressure tube termination 16. Cleaning cell: permeate 17.Cleaning cell: water supply 18. Water inlet valve 19. Connection line HDdevice (permeate line) 20. Conductivity cell (LF cell) 21. Hemodialysisdevice (HD device) 22. HD flushing valve 23. HD water inlet valve 24. HDwater inlet container with float or level sensors 25. HD pump 26. HDflushing line 27. Degassing throttle 28. Degassing bypass valve 29. HDheater 30. Degassing chamber 31. HD circulation line 32.Concentrate/bicarbonate supply 33. Outlet 34. Flushing valve 35. Flowresistance 36. Concentrate line 37. Buffer chamber 38. Circulation pump39. Pressure raising pump 40. Electrodes 41. Membrane 42. Combinationcleaning cell 43. Outer electrodes 44. Inner electrode 45. Coil winding46. Ultrasound 47. Accommodation sealing ring 48. Insulation tube 49.Feed line

The invention claimed is:
 1. A combination comprising a single-stationreverse osmosis device (RO device) with a hemodialysis device (HDdevice), the RO device comprising a filter with a membrane whichseparates a primary circuit from a secondary circuit, a raw-water supplyline terminating in the primary circuit and the secondary circuit beingconnected to a permeate inlet valve of the HD device via a connectionline containing a conductivity measuring device, and a concentrateconnection of the primary circuit leading to an outlet via a concentrateline containing a flow-resistance means, wherein at least one cleaningchamber for at least one of the raw water and the permeate is connectedto the RO device, and that upon request by the HD device, the permeateflows either via the permeate inlet valve into the HD device or via aflushing valve of the HD device to the outlet.
 2. The combinationaccording to claim 1, wherein the secondary circuit comprises a permeatecollection tube.
 3. The combination according to claim 2, wherein saidat least one cleaning chamber comprises a permeate cleaning chamber inthe permeate collection tube.
 4. The combination according to claim 3,wherein the permeate cleaning chamber is installed into an end sectionof the permeate collection tube facing away from the connection line. 5.The combination according to claim 1, wherein said at least one cleaningchamber comprises a water supply cleaning chamber inserted into theraw-water supply line.
 6. The combination according to claim 1, whereinthe at least one cleaning chamber includes oxidants for fightingmicroorganisms.
 7. The combination according to claim 6 wherein the atleast one cleaning chamber includes at least one of electrical,magnetic, electromagnetic, electrolytic, and sonographic means on theliquid flowing therethrough.
 8. The combination according to claim 1,wherein the at least one cleaning chamber includes agents forstabilizing lime crystals dissolved in water.
 9. The combinationaccording to claim 8 wherein the at least one cleaning chamber includesat least one of electrical, magnetic, electromagnetic, electrolytic, andsonographic means on the liquid flowing therethrough.
 10. Thecombination according to claim 1, wherein a recirculation line providedwith a pump connects the concentrate line upstream of theflow-resistance means to the raw-water feed line upstream of the atleast one cleaning chamber.
 11. The combination according to claim 1,wherein the connection line is provided with a permeate buffer chamber.12. The combination according to claim 1, wherein the flushing valve isconfigured such that the flushing valve can open the flow-resistancemeans.
 13. The combination according to claim 1, wherein the membrane isan exchangeable disposable membrane.
 14. The combination according toclaim 1, wherein said at least one cleaning chamber comprises a permeatecleaning chamber in a permeate collection tube, and a water supplycleaning chamber inserted into the raw-water supply line.